Yes, it's possible. For example, French people abroad can simply vote in their consulates, the same way than other national elections. Their votes will simply be added to one of the districts (namely Paris/Île-de-France). Obviously, the precise modalities will depend on the country (not all countries vote on the same day, etc.) and it seems that countries don't even *have* to provide a way to vote for their citizens abroad but at least it's not forbidden as far as the EU is concerned. [European citizens abroad](http://www.europeancitizensabroad.eu/) is an organization devoted to this topic. Here is [their page about the Netherlands](http://www.europeancitizensabroad.eu/netherlands.html).